Automatic thread-tapping machine



F. H.. KIND. AUTOMATIC THREAD TAPPING MACHINE.

APPLICATION FILED MAR. 22, 1920-- Patented Jan. 10, 1922,

3 SHEETS-SHEET 1.

F. H. KIND. AUTOMAHC THREAD TAPPINGVMACHINE.

APPLICATION HLED MAR. 22, 1920.

Patented Jan. 10, 1922.

1 3 SHEETS-SHEET 2. F I? Z Frederick I-LPQ'ncL- F. H. KIND.

AUTOMATIC THREAD TAPPING MACHINE.

APPLICATION FILED MAR. 22, 1920.

1,403, 1 70, Patenbed Jan. 10, 1922,

3SHEETS-SHEET 3- FIEEIEIlEk H Kind f W @M'oma UNITED STATES.PATENTOFFICE.

FREDERICK H. KIND, 19F MANITOWOC, WISCONSIN ASSIGNGR TO W. G-ATEBMANZdFG.

' i (30., 0F MANI'POWOC, WISCONSIN.

AUTOMATIC THREAD-EAPPING MAGHINE.

onaco. 7 Application To all whom it may concern:

Be it known that L FREDERICK KIND, a citizen of the United States, andresident of Manitowoc, in the county of Manitowoc and State ofWisconsin, have invented certain new and useful Improvements inAutomatic Thread-Tapping Machines; and 1 do hereby declare that thefollowing is a full, clear, and exact description thereof.

My invention relates to new and useful improvements in drilling andtappinginachinery and has particularret'erence to the latter type ofnachines.

The primary object or" the present invention resides'in the provision ofa machine of this character with automatic means for reversing thedirection of normal operation of a .tool or tap when a predeterminedstrain is placed thereon, thus rendering it impossibleto feed a tool tothe work at too great a speed and eliminating the customarymanualprecaution for preventing the same from being forced into hard spotspresent in the metal, which results'in breakage to the tool.

It is a secondary object ofthe invention to provide automatic alternaterotation of a drill or tap so that the samemay befed indeterminatedistances into the work as-well as given a limited numberof revolutionsor a portion of a revolution ina non-working direction. I

It is a further object of this invention to carry out the operationsthereof by means of electricity. 4

With these general objects in view themvention resides in the novelfeatures of construction, combination'and arrangement of parts whichwill be hereinaftermore particularly described and claimed andshown inthe accompanying drawings wherein:

Figure 1 represents a transverse sectional view through a drilling andtapping machine constructed in accordance with my invention.

Figure 2 is a plan view of the main drive specification 01 LettersPatent.

Patented J Z 922.

As is usual in machines of this character the spindle operatingmechanism is mounted upon a bracket 1 spaced above a suitable work-table(not shown) by a standard or column 2. The portion of the bracket whichwould be normally disposed above said worktable is shaped to form aspindle housing 3 in which a spindle 4 is rotatable and verticallyreciprocable; the lower end of this spindle carries the usual drill ortap chuck 5. The lower half of the spindle i is surrounded-by thenon-rotatable feed-sleeve 6, the same having a plurality of teeth 7which cooperate with the similar elements of a feed pinion 8. The shaftof the pininn 8 has a- Figureil it will be noticedthat the plate 14:-

isseated on the shoulder 16 at the base of the bearing 10, it beingsecured thereto in any preferred or desired manner.

connector plate 17 surrounding the spindle 4 seats against the upper endof the rotate to bearing 10 and the similar face of the gear 12, and iskeyed as at 18 to said spindle. Connection between this plate 17 and thegear 12 is provided through a slotted arm 19 projecting from the formerand a spring rod 20, the latter being pivoted at one end as at 21 tothis gear 12,.and a'djustably joined with the said arm 19 as shown at22. The rod 20 is designed to slide through the connection 21, and isurged against such movement by means of an expansile coil spring 23surrounding the same and having one end en gaged with said connection 21and the other end with an adjustable nut 24. An expansile coil spring 25surrounds the spindle i above the conductor plate 17 and has one endbearing thereagainst, the other or upper end being in engagement with astop collar 26. This spring 25' obviously causes the spindle 4 to moveupwardly within its housing 3 upon the release of the feed arm 9.

' The gear 12 is preferably of a bevel or mitre type and its teeth aredesigned to be '27, together with the connector plate 17 Housedwithinthe pulleys 31 and 32 is a clutch mechanism for selectivelylocking either of the same to the shaft 28. This clutch mechanismincludes a clutch head 34 which has a pair of arms 35 fixed to the shaft28 as at 36, said head being adapted to carry a pair of clutch pins 37and 38, the former being for cooperation with clutch teeth 39 on theforward pulley 31,

whereas the pin 38 co-acts with teeth 40 on the reverse pulley 32 whenbrought into engagement therewith.

The head 34 also carries a shifter 41 for selectively moving the clutchpins 37 and 38 into engagementwith the teeth 39 and.

40 respectively. said shifter including arms 42 for co-action with saidclutch pins, and an arm 43 for rocking the same. This actuating arm 43projects into a bore 44 in the shaft 28 through a slot 45 therein and isengaged on one side by a bearing ball 46 and on its opposite side by aclutch rod 47, both of which elements are slidable in said bore. Theball 46 is urged against the arm 43 by an expansile spring 48 locatedwithin said bore. said spring also exerts its tension to hold the clutchrod 47 in engagement with the transverse pin 49 of a sliding collar 50,the same being movable longitudinally on the shaft 28. Such movement is,however. limited by the ends of slots 51 in the shaft 28 through whichsaid pin 49 extends.

One of the bearings 33has an electromagnet casing 52 mounted thereon inwhich is disposed a usual electromagnet 53, the armature 54 of which iscarried by a pivoted arm This arm is hung within the casing 52 and itslower end projects through a slot 56 therein and engages with thesliding collar 50. In addition to the armature 54. the arm also carriesa contact 57 for engagement with the contact 58 on the magnet 53. Itwill be seen that by energizing the electromagnet 53, the collar 50 willbe slid toward the pulleys 31 and 32 to move the clutch rod 47 in thesame direction with the result that the clutch pin 37 vis engaged withone of the clutch teeth 39 while the other clutch pin is renderedinactive. On the other hand when the magnet is deenergized, the spring48 moves the shifter 41, the clutch rod 47 and the collar 50 in theopposite direction to thus throw the clutch pin 38 into engagement withone of its teeth 40 and disconnect the clutch pin 37 from its teeth 39,as shown in Fig. 1.

The means for making and breaking the circuit of the electromagnet iscontained largely within the casing 15 and is directly controlledthrough the connector plate 17. Therefore referring more particularly tothe portion of the figures illustratingthese parts, it will be seen thatthe under side of the gear 12 is provided with conductor rings. 59 and60, a brush 61 being provided for engagement with the former. and asimilar brush 62 with the latter, both of which brushes are supportedupon the carrying plate 14 and have binding posts 63 project ing fromthe casing 15. The hub 11 of the gear 12 is provided with a split orslip collar 64 having a radially extended trip arm 65; engagementbetween the-hub 11 and the collar 64 is such that when the arm 65 isengaged with an adjustable stop 66 by the rotation of the gear 12 in onedirection, the same will slip, but when the gear 12 is rotated in thereverse direction, and the trip arm 65 brought into contact with one arm67 of an auxiliary circuit switch 68, said collar will bind upon the hub11 and be moved therewith with the result that the switch 68 is closed.

The switch 68 includes a bell crank, one of its arms being the arm 67and the other carrying a spring contact 69 for engagement with astationary contact 70 formed on the brush 62. A contractile spring 71connected with the arm 67 and the plate 14 normally rotates the switch68 to an open position, that is to say moves the spring contact 69 awayfrom the stationary contact 70.

The hereinbefore mentioned adjustable stop 66 is carried by a crank arm,the shaft of which projects through the plate 14 and has an externaladjusting arm 72. This arm 72 is of spring material and carries a detent73 at its free end which is adapted to spring into any one of anareaately arranged series of sockets 74. Thus by shifting the adjustablestop 66, it may be moved'to greater or less distances from the arm 67 ofthe switch 68.

Exteriorly of the casing 15 is located a main circuit switch 75. thesame including a spring contact 76 having one end secured to the gear 12and electrically connected with the conductor ring 60. The other portionof this switch 75 includes a stationary contact 77 also electricallyconnected with the conductor ring 59 and arranged to be engaged by thespringcontact 76 by means of a switch finger 78 extending from theconnector plate 17.

A. third or main switch also forms a part of the electromagnet circuitsand is manually controlled by the operator of the machine the other twoswitches above referred to being automatically opened and closed. Inother words this main switch is disposed on the feed arm 9 and comprisesa main switch lever 79, a movable or spring contact 80 and a stationarycontact 81. When the operator forces downwardly on the free end of thefeed lever 9 he automatically rocks the switch lever 79 and moves thecontact 80 into engagement with the contact 81, thus making a circuit.

Referring now to Figure 4, the means for connecting the parts of theseveral switches with the electrom'agnet will be described. One, linewire 82 connects directly with'the eleotromagnet 53, whereas the otherline wire 83 runs to the stationary contact 81 on the main switch, thecurrent after entering the" movable contact 80 flowing through aconducting wire 84 to the brush 62. After flowing through the maincircuit switch, provided the same is closed, the current runs from thebrush 61 through a conducting wire 85 to the contact 57 of the swingingarm 55, through the spring contact 58 of the electromagnet, thencethrough the coils of the same by way of a conducting wire 86. Thiscircuit may be termed the main circuit and as long as -it is completethe electromagnet will be energized and the spindle 4 rotated in anoperative direction.

That circuit which for the sake of convenience in description may bereferred to as the auxiliary circuit includes a line wire 83, the mainswitch, the conducting'wire 84, the brush 62, the auxiliary switch 68,and the conducting wire 87. This latter conducting wire is connectedwith the spring contact 58 and the current after passing therethroughand into the electromagnet 53 flows out to theline through the line wire82.

The operation of my invention may be briefly described as follows:Assuming that a tap has been secured in the chuck 5 and the main circuitswitch manually closed by the pressure of the operators hand ontheswitch lever 79, the main switch above referred to will be closed andthe electromagnet 53 energized which will cause the forward pulley 31 tobe locked to the drive shaft 28 as hereinbefore particularly set forth,and the rotation of this pulley will be imparted to said shaft andthrough the gears 12 and 27 and the connector plate 17 to the spindle4'. As long as the workman continues to feed the tap to the work in aproper mannerand at the required rate of speed, or as long as the tap iscutting through metal which offers only an average resistance, theelectromagnetwill remain energized and the spindle will revolve in anoperative direction. However, as soon as the tap meets with more thanthe usual predetermined resistance, the

rotation of the spindle will tend to lag with respect to that of thegear 12, this being readily possible through the instrumentality of theconnector plate and the spring connection between it and said gear 12,thus moving the switch finger 78 away from the spring contact 76-andbreaking the main circuit switch 75. Since the switch 75 is open, themain circuit will be broken and the elec-- tromagnet immediatelydie-energized wit the result that the reverse pulley is thrown intooperation and the shaft 28 rotated in a direction the reverse of that atwhich it was just previously revolved. Consequently the spindle 1 willbe revolved in a reverse or non-operative direction, and this rotationwill continue until the normally open auxiliary switch 88 is closed. Ashereinhefore mentioned the auxiliary switch 88 is closed by engagementby the trip arm with the switch arm 87. As soon as the auxiliaryswitch'is closed, the electromagnet will be again energized and thearmature 54 attracted thereto; thenormal direction of rotation of theseveral parts of the machine is thus again obtained.

1f, when the tap is a second time rotated in an operative direction, itmeets with unusual resistance, the main circuit switch will be a secondtime opened as hereinhefore set forth. This alternate rotation of thetap in opposite directions will continue in this manner until theresistance is gradually overcome. Although the spindle may rotate K asmany revolutions in an operative direction as necessary, it can onlyrotate a predetermined distance in a non-operative direction,

this distance being controlled byadjusting the stop 66. In other wordswhen the spindle isrotated in an operative direction the trip arm 65lies in engagement with the stop 66 and. is moved away from same whenthe spindle'is rotated in a non-operative direction. Therefore thedistance which the trip arm 65 travels from the stop 66 to the arm 67 ofthe switch 68 regulates the amount of nonoperative operation of thespindle. g,

The ease with which the finger 78 of the connector plate is moved awayfrom the spring contact 76 is also regulatable. This being accomplishedthrough the slotted arm 19 and the connection 22 of the spring rod ,20.In other words the degree of movement between the carrying plate and themain drive gear is adjustable so as to make the action of the variousparts of the invention more or less responsive to the resistance torotation of the spindle. The spring 23 which surrounds the rod 20 inaddition to forming a connection betweenthe connector plate and the gear12 provides a cushioning means to' absorb the shock which is incident tothe striking of the work by the tap or other tool.

Various changes may be roads in the form or proportionsof the severalparts of the invention and in the general association of these partswithout departing from the principles of the invention or sacrificingany of 5 the advantages.

I claim 1. In a mechanism of the character dcscribed,'a toolcarrying-spindle, means for rotating the spindle in one direction, meansfor automatically discontinuing rotationpf the spindle in said directionfora predetermined length of time when resistance to rotation of saidspindle reaches a predetermined degree, and means for varying the lengthof time of non-rotation of the spindle in .said direction.

2. In a mechanism of the character described, a tool carrying spindle,and means terminate, and the amount of rotation in the reverse directionbeing predetermined, and means for varying the predetermined amount ofrotation in said reverse direction. 4. In a mechanism of the characterdescribed, a tool carrying spindle, means for rotating the spindle inone direction, means for discontinuing rotation of the spindle in saiddirection, means for rotating the spindle a predetermined distance in areverse direction, and means for automatically rotating the spindle inthe initial direction when same has rotated said" predetermined distancein the reverse direction.

5. In a mechanism of the character de-- scribed, a tool carryingspindle, means for rotating the spindle in one direction,electromagnetic means for discontinuing rotation of the spindle in saiddirection, means for rotating the spindle a predetermined distance in areverse direction, and means for automatically rotating the spindle inthe initial direction when thesame has rotated said predetermineddistance in the reverse direction. x

6. In a mechanism of the character described, a tool carrying spindle,means for rotating the spindle in one direction, electromagnetic meansfordiscontinuing rotation of the spindle in said direction, means forrotating the spindle a predetermined distance in a reverse direction,and electromagneticmeans for starting rotation of the spindle in theinitial direction when the same has rotated said predetermined distancein the reverse direction.

7. In a mechanism of the character described, a tool carrying spindle,means for rotating the spindle in a forward direction, means forrotating the spindle in a reverse direction, an electromagnet foractuating the said means, a switch, an electriccircuit including saidswitch and electromagnet, said circuit being normally complete wherebythe spindle will be rotated in a forward direction, and means operableby the spindle to open the switch and break the circuit when rotation ofthe spindle is resisted. I

8. In a mechanism of the character described, a tool carrying spindle,means for rotating the spindle in a forward direction, means forrotating the spindle in a reverse direction, an electromagnet foractuating the said means,'a switch, an electric circuit including saidswitch and electromagnet, said circuit being normally complete wherebythe spindle will be rotated in a forward direction, means operable bythe spindle to open the switch and break the circuit when rotation ofthe spindle is resisted, and means for automatically remaking thecircuit after a predetermined space of time.

In testimony that I claim the foregoing I have hereunto set my hand atManitowo'c,

in the county of Manitowoc and State of Wisconsin.

FREDERICK H. KIND.

